TY  - CHAP
M1  - Book, Section
TI  - Practice Advisory for Perioperative Visual Loss (POVL) Associated with Spine Surgery
A1  - Bailin, Michael
A1  - Spanakis, Spiro
PY  - 2000
T2  - Guidelines
AB  - |PrintPractice  Advisory  for  Perioperative  Visual  Loss  (POVL)  Associated  with  Spine  SurgeryComments  by  Michael  T.  Bailin,  MDDefinitionsPreoperative  Considerations  &  RecommendationsIntraoperative  ManagementPostoperative  CareSummary  Statements/EvidencePerioperative  visual  loss  (POVL):  Permanent  impairment  or  total  loss  of  sight  associated  with  a  spine  procedure  during  which  general  anesthesia  is  administeredThese  may  be  risk  factors  for  POVL:  Vascular  factorsPreop  anemiaLong  proceduresHigh  blood  lossCombination  of  long  procedure  with  large  blood  lossPlan  to  assess,  reassess,  and  document  the  eyes  and  head  position  of  prone-positioned  patients.Assess  the  high-risk  patient’s  vision  when  the  patient  becomes  alert.No  prospective  clinical  trials  on  POVL  had  been  performed  by  the  time  of  publication.Case  reports  have  reported  POVL  after  procedures  with  large  blood  loss  and  hypotension.High-risk  patients:  Those  who  undergo  spine  procedures  while  positioned  prone  and  who  have  prolonged  procedures,  experience  substantial  blood  loss,  or  bothConsider  informing  a  high-risk  patient  of  the  rare  possibility  of  POVL.There  is  no  proven  therapy  to  prevent  perioperative  ION.Blood  pressure  management  for  high-risk  patients:  Chronic  hypertension  may  indicate  need  for  higher  intraoperative  blood  pressure.Systemic  blood  pressure  should  be  continually  monitored  in  high-riskConsider  increasing  hemoglobin  levels,  blood  pressure,  and  administering  oxygen  in  high-risk  patients  when  ION  is  suspected.Other  risk  factors  associated  with  POVL  include  hypertension,  glaucoma,  carotid  artery  disease,  smoking,  obesity,  and  diabetes.Prolonged  procedure:  Exceeding  an  average  of  6.5  hoursConsider  discussing  staging  the  procedure  with  surgeon  (if  lengthy  and  has  potential  for  large  blood  loss).Deliberate  hypotension  not  indicated  in  high-risk  patients,  but  may  be  used  in  selected  cases.Intravascular  volume  should  be  continually  monitored  in  high-risk  patients.Urgent  ophthalmologic  consultation  should  be  obtained  when  POVL  is  suspected.The  advisory  concluded  that  preoperative  ophthalmic  or  neuro-ophthalmic  assessment  would  not  prevent  POVL.Substantial  blood  loss:  When  blood  loss  reaches  an  average  of  44.7%  estimated  blood  volumeConsider  discussing  head  positioning  with  surgeon:  Level  with  or  higher  than  heartWhen  feasible,  position  a  high-risk  patient’s  head  in  a  neutral  forward  position.Colloids  should  be  used  along  with  crystalloids  to  maintain  intravascular  volume  in  patients  who  have  substantial  blood  loss.  Central  venous  pressure  monitoring  should  be  considered  in  high-risk  patients.No  transfusion  threshold  would  seem  to  eliminate  the  risk  of  POVL  related  to  anemia.Advisories:  There  are  seven  main  headings.  1.  Blood  Pressure  Management2.  Management  of  Intraoperative  Fluids3.  Management  of  Anemia4.  Vasopressors5.  Patient  Positioning6.  Surgical  Procedures7.  Postoperative  ManagementUsing  a  horseshoe  headrest  may  increase  the  risk  of  ocular  compression.Hemoglobin  or  hematocrit  levels  should  be  periodically  monitored  during  surgery  in  high-risk  patients  who  experience  substantial  blood  loss.Using  alpha  adrenergic  agonists  should  be  made  on  a  case-by-case  basis.No  studies  examine  the  use  of  vasopressors  in  relation  to  POVL.Ophthalmic  conditions  addressed  in  POVL  advisory  are:  Posterior  ischemic  optic  neuropathy  (PION)Anterior  ischemic  optic  neuropathy  (ION)Central  retinal  artery  occlusion  (CRAO)Not  addressed  in  advisory:  Management  of  patients  under  regional  block  or  monitored  anesthesia  careOther  causes  of  visual  loss,  such  as  cortical  blindnessNon-spine  or  non-prone  surgical  proceduresVisual  loss  in  patients  under  12  years  
SN  - 
PB  - The McGraw-Hill Companies, Inc.
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessanesthesiology.mhmedical.com/content.aspx?aid=5010033
ER  -